摘要：A characteristic wavy morphology often appears at the joint interface of magnetic pulse welding (MPW), and an intermediate layer is formed in some metal combinations. It has been known that the wavy morphology changes mainly depend on the density difference between the metals. A sinusoidal wavy interface is formed for the combination of similar metals (Al/Al, Cu/Cu) and that of dissimilar metals having almost the same density (Cu/Ni). In contrast, a trigger-like wavy interface is formed for the combination having a large density difference (Al/Cu, Al/Fe). The difference in strength (hardness) of the solid metal is also assumed to affect the wavy interface morphology. In the present study, two metal combinations (Al/Cu and Al/Ni) were subjected to the MPW to elucidate the effect of hardness difference, since Cu and Ni have almost the same density, but different hardness. Both the MPWed Al/Cu and Al/Ni joints showed a trigger-like wave interface. The wave size (wave-height and wavelength) of Al/Ni was smaller than that of Al/Cu. In Al/Ni, the distribution of intermediate phase was more continuous tracing the outline of the wave. The numerical simulation of the wave formation process was performed using the Smoothed Particle Hydrodynamics (SPH) method. It was revealed that the extent of metal jet penetration into the metal in the process of joining behind the collision point was weaker in Ni than in Cu. This is considered to be due to the larger deformation resistivity of Ni, which is harder than that of Cu.
